I am a fairly experienced distance runner, and much of what you say is legitimate. Besides that, the striking of the foot is also important as well. Preferably, striking in the mid-foot not only ensures the preservation of balance, but also helps to lengthen your stride without overextending (although preferences tend to vary, but the forefront is more so for sprinting while the heel can lead to shin strains if overdone). Otherwise, it's never too late to start running, especially if done at your own pace. Once you know where to start, the progress can only go up with patience and dedication.